Hydraulic corrugating machine



Sept. 16, 1952 L. M. PUSTER 2,610,667

HYDRAULIC CORRUGATING mcmm:

Filed July 2. 1947 11 Sheets-Sheet 1 icil I'uvemfior, Louis M Pusielr Sept. 16, 1952 PUSTER 2,610,667

HYDRAULIC CORRUGATING MACHINE Filed July 2. 194' ll Sheets-Sheet 2 lnvenor Louis MPusterv '..x BY f s" p 15, 1952 M. PUSTER 2,6 7

HYDRAULIC CORRUGATING MACHINE Filed July 2, 1947 i I ll Sheets-Sheet 3 3 rwa/wtoo .DOup'JM Pucker. I

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I HYDRAULIC CORRUGATING MACHINE Filed July 2, 1947 ll Sheets-Sheet 4 Qvwe/MM Louis M Pusher.

Se t. 16, 1952 v PUSTER 2,610,567

HYDRAULIC CQRRUGATING MACHINE Filed July 2, 1947 11 Sheets-Sheet 5 Louis MPuskr Wmzmrm L. M. PUSTER HYDRAULIC CORRUGATING MACHINE Sept. 16, 1952 ll Sheets-Sheet 7 Filed July 2, 1947 Sept. 16, 1952 M, PUSTER 2,610,667

HYDRAULIC CORRUGATING MACHINE Filed July 2, 1947 7 ll Sheets-Sheet 8 /--V-\ YIAVI L Invulbor 62 56 MPuster.

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HYDRAULIC CORRUGATING MACHINE Filed July 2, 1947 ll Sheets-Sheet 10 HITURN YO TANK INVENTOR Sept. 16, 1952 PUSTER 2,610,667

HYDRAULIC CQRRUGATING MACHINE Filed July 2. 1947 11 Shoots-Sheet 11 Fig. 12'

I lure rLtar Louis-M. Pusfler.

apm mwm Attormeys Patented Sept. 16, 1952 2,610,667 HYDRAULIC CORRUGATING MACHINE Louis M. Puster, Knoxville, Tenn., assignor to Robertshaw-Fulton Controls Company, a corporation of Delaware Application July 2, 1947, Serial No. 758,66 i

14 Claims.

This invention relates to hydraulic presses and more particularly to hydraulic presses for forming expansible and contractible corrugated metallic walls.

Heretofore various devices have been proposed for forming expansible and contractible corrugated metallic walls by spacing forming plates along a metallic tube at regular intervals, thereafter expanding the tube by internal hydraulic pressure until bulges form in the tube between plates, and thereafter forcing the forming plates toward each other to form corrugations in the tube between plates. Among such previous devices is that of the United States Patent No. 2,217,799, granted to Jean V. Giesler on October 15, 1940. In these devices many of the steps in the process of forming the expansible and contractible walls have been performed manually, slowing the production rate, and have introduced certain difficulties arising from the human factor of the operators.

The present invention obviates these prior difiiculties, in a device that continues to use the broad idea of forming expansible and contractible metallic walls by spacing equidistantly a plurality of forming plates along a metallic tube, expanding the tube by hydraulic pressure forming bulges in the tube between the forming plates and thereafter forcing the forming plates together to form the desired corrugationsin the tube,by providing automatic operation in the sequence of its functions thus producing a uniform product at greatly increased rates. In the present invention the operator places the metallic tube to be formed into the expansible and contractible wall on an arbor which is thenautomatically moved within the forming plates. When the tube reaches its final position within the forming plates the open end or ends of the tube are auto matically closed. The forming plates are then automatically locked about the tube. When the forming plates are locked together hydraulic pressure is automatically exerted within the tube to form bulges in the tube between the forming plates. When the hydraulic pressure reaches a predetermined value it is thereafter automatically maintained at this pressure and at the same time suitable means are automatically energized which, at the start of their cycle, remove the spacers from between the forming plates. After removal of these spacers these means continue their cycle automatically to effect the formation of the desired corrugations in the tube between the plates as the latter move toward each other. When the plates reach a predetermined relationship the hydraulic pressure within the. now

the forming plates unlocked and opened,the com- I pressing force is automatically terminated. and

reversed and the arbor, with the now formed corrugated wall upon it, returned to its original position outside of the forming plates. The formed wall is then removed from the arbor. With the return of the forming plates to their original position mechanical means automatically return the spacers between the several forming plates. Another tube is then placed on the arbor in readiness for another forming cycle.

It isan object of this invention to provide a novel hydraulic press in which the several steps of forming the expansible and contractible wall are automatically performed at the proper time.

Another object of this invention is to provide a novel hydraulic press in which novel means are automatically actuated when the tube is in final position within the forming plates to automatically seal the open end .or ends of the tube.

Another object of this invention is to provide a novel hydraulic press in which novel means are automatically actuated to introduce hydraulic pressure within the tube before the end or ends of the tube are sealed and to thereafter seal theactuated after the end or ends of the tube have been sealed but before the generation of bulging pressure to close and lock the forming plates about the tube.

Another object of this invention is to provide a novel hydraulic press in which novel means are automatically put into rectilinear movement when the hydraulic pressure within the tube has reached a predetermined value the initial movement of which acts to remove the spacers from between the forming plates.

Another object of this invention is to provide a novel hydraulic press in which novel means are automatically actuated when the forming plates have moved toward each other a predetermined amount to release the hydraulic pressure acting on the wall.

Another object of this invention is to provide a novel hydraulic press in which novel means are provided for automatically unlocking and opening the forming plates when the hydraulic pressure within the formed wall is released.

Another object of this invention is to provide a novel hydraulic press in which novel means are provided for automatically returning the end sealing means with the formed wall upon it to its initial position outside of the forming plates as soon as the forming plates have been unlocked and opened.

Another object of this invention is to provide a novel hydraulic press in which novel means are provided for mechanically interposing the spacers between the forming plates at the proper time in the cycle of operation of the press.

Another object of this invention is to provide a novel hydraulic press in which novel means are provided for mounting the forming plates for automatically closing and locking and for unlocking and opening, all at proper times in the cycle of operation of the press.

Another object of this invention is to provide a novel hydraulic press in which novel means are provided for adjusting the relative position of the spacers.

Another object of this invention is to provide a novel hydraulic press which can be reversed at any time in its cycle of operation to return the several elements thereof to their initial positions in proper sequence without damage to the machine.

Other and further objects of this invention will appear as the description thereof proceeds.

With these objects in view an illustrative embodiment of the novel hydraulic press of the present invention is shown in the accompanying drawings but it is to be expressly understood that this embodiment is shown and will hereafter be described for the purpose of illustration only and should not be construed as a limitation of the present invention. Reference should be had to the appended claims to determine the scope of the present invention.

In the accompanying figures,

Figs. 1 and 1a are together a front view of one embodiment of my novel hydraulic press;

Figs. 2 and 2a are together a top view of the embodiment-of my novel hydraulic press shown in Figs. 1 and 1a;

Fig. 3 is an enlarged view of a portion of Fig. 1 showing a typical forming plate in locked position, a novel plate locking means, the novel spacer removing means, the novel means for closing and locking and unlocking and opening theplates and the novel mechanical means for interposing the spacers between the plates:

Fig. 4 is a similar view to Fig. 3 showing the forming plates in unlocked and open position and the novel mechanical means for interposing the spacers between the plates in engagement with certain of the spacers;

Fig. 5 is an enlarged perspective view of a portion of Fig. 1 showing the novel cradle for supporting the forming plates, spacers and separators;

Fig. 6 is a perspective and enlarged view of a portion of Fig. l partly in section showing the novel means for removing the spacers from betweenthe forming plates.

Fig. 7 is an enlarged sectional view of a portion of Fig. 1 through the forming plates showing in more detail the novel means for supporting the spacers and forming plates in the cradle and the position of the novel spacer removing means.

Fig. 8 is an enlarged sectional view of a portion of Fig. la showing in more detail the novel tube supporting and end sealing means;

Fig. 9 is a simplified piping diagram of the hydraulic system shown in Figs. 1 and la;

Fig. 10 is an enlarged view of a spacer separator;

Fig. 11 is an enlarged View of a spacer; and

Fig. 12 is a simplified partial piping diagram of a suitable modified hydraulic system for use with this invention.

In the several figures, in which like reference characters indicate similar parts, and more particularly with reference to Figs. l-8, II is any suitable machine bed slotted at l2 for mounting the several parts of the device and supported by suitable legs I3. Mounted at one end of bed II are brackets M and I5 between which is carried a spacer reset piston and cylinder l6, and a closing or ram piston and cylinder I7, bolts |8 acting to hold the assembly together. Fluid under pressure is admitted to one side of the piston in cylinder l6 through hand-adjustable valve l9 and to the other side of the piston through handadjustable valve 20. Fluid under pressure is admitted to one side of the piston in cylinder I! through hand-adjustable valve 249 and to the other side of the piston through pipe 25|. The hydraulic system for operating these pistons in timed sequence in the cycle of operation of the machine will be described hereinafter in detail.

Mounted on bed beyond bracket |5 are cradle brackets 23 and 24. Bracket 24 carries upstanding elements 25 and 26 which in turn carry parallel rods 21 and 28 which are secured at their other ends to bracket I5 as at 29 and 33. Mounted for reciprocating movement on said rods 21 and 28 is spacer reset head 3| which is operated by the piston in cylinder l6 through piston rod 32 that is secured to head 3| by manually operable lock 33. As seen in Figs. 3 and 4 spacer reset head 3| is provided with outwardly and downwardly extending parts 34 and 35 to which housings 38 are suitably secured as by bolts 36 and keys 31. Reset rollers 39 and 4! are rotatably mounted in housings 3B. Rollers 39 and 40 are offset at their centers of rotation for reasons that will more fully appear hereafter.

Referring now more particularly to Figs. 3, 4 and 5, brackets 23 and 24 support a rod 4| extending parallel to the center line of bed Pivotally mounted on rod 4| are cradle end elements 42, 43, 44 and 45. Elements 42 and 43 are pivotally mounted at 45 and together form one end of the cradle while elements 44 and 45 are pivotally mounted at 41- and together form the other end of the cradle. Elements 42 and 43 are kept in spaced relationship with elements 44 and 45 by spacer guide bars 49 and 49 on the one side and by spacer guide bars 50 and 5| on the other side. These guide bars are fixed to the cradle end elements in parallel relationship. Each guide bar is longitudinally slotted as at 52 and 53 for bars 48 and 50 and at 54 and 55 for bars 49 and 5| respectively to carry spacer locks 56 and 51. Mounted for reciprocating movement between the guide bars are a plurality of spacers 58 separated by separators 59 and limited in outward movement by stop members 60 and SI carried by the cradle end elements.

As seen in Figs. 7, l0 and 11 the spacers 58 are of generally rectangular shape slotted at 62 and beveled at 63 for insertion between the forming plates as will more fully appear hereafter. Spacers 58 are also beveled at 64 for engagement by the reset rollers 39 and 40. The separators 59 are more or less i-shaped in plan and have slots 65 corresponding to slots 82 of spacers 58. Separators 59 have ears 6G and 61 formed integrally therewith and when in place between the guide in turn pivoted to element 43 at I01.

bars these cars are received by the slots 52-54 and 53-55. The thickness of separators 59 is determined by the thickness of the forming plates. A separator 59 is placed between each two adjacent spacers 59 and the number of such spacers and separatorsused in any setup of the machine is determined by the number of forming plates used which in turn is determined by the number of corrugations desired in the wall to be formed.

Spacer locks 55 and 51 hold spacers 58 and separators 59 together between the guide bars. As seen in Fig. '1 lock 55, which is duplicated by lock 51, comprises a'body portion 68 mounted between the guide bars and locked in place by bolts 69 extending through slot 52 and cooperating with plate 10. Body portion 68 is drilled at H to receive springs 12 and bearing balls 13 which are resiliently urged against the adjacent separator 59 to pack the spacers and separators together and yet allow reciprocating movements by the spacers.

Spacers 50 are withdrawn from between the forming plates by square bars 14 and 15 moving in the slots 62 of the spacers 58 and in the slots 65 of separators 59. The ends of bars 14 and 15 are rounded (Fig. 6) andare received in rounded slots 16-49 in rocker arms 8083 respectively. Arms 89 and iii are secured to a rocker shaft 84 journaled in cradle end elements 42 and 44 and arms 82 and 83 are securedto a rocker shaft 35 journaled in cradle end elements 43 and 45. The rocker arms are located on the outside of the cradle end elements and the cradle end elements are suitably cut away to allow movement of bars 14 and 15. Arms 89 and 82 arerocked by cam followers 85 and 81, respectively, which are pivotally mounted at 88 and 89 on bracket 85. Cam follower 86 has a suitable manually ad justable cam engaging element 90 and cam follower 81 has a similar element 9| both'of which cooperate with cam 92 carried by the piston rod 93 of the piston mounted in cylinder I1.

Cradle end elements 42 and 44, carrying their guide bars, separators and spacers, are rotated about rod 4| by rocker shaft 94 which is journaled at one end in bracket 23 and at the other end in bracket 24. Rocker shaft 94 is linked to element 42 through rocker arm 95 which is secured to shaft 94 and link 96 which is pivoted to element 42 at'91 and to arm 95 at 98. Rocker, shaft 94 is also linked to element 44 through rocker arm 99 which is secured to shaft 94 and link I30 which is pivoted to element 44 at HM and to rocker arm 92 at I02. Cradle end elements Y43 and 45 carrying their guide bars, separators and spacers are rotated about rod 4! by an identical mechanical arrangementbest seen in part in Figs. 3 and 4 where I03 is the rocker shaft, I04 a rocker arm pivoted at I05 to link I06 which is Rocker is carried by and secured to cradle end elements shafts 94 and 83 are rotated byL-shaped arms I03 and I09, best seen in Fig. 4, which are secured to shafts 94 and IE3, respectively, adjacent each other at the ends of their longer arms. Arm 199 is provided with an L-shaped slot H9 and arm I08 is provided with a corresponding slot. III. Driving rollers H2 are mounted in slots HO and III and are in turn rotatably mounted on shaft II3 carried by slide H4. Slide II4 is mounted for vertical reciprocating movement in tracks II 5 secured to bracket 23 and extending downwardly into slot I2 of machine bed II. Slide H4 is reciprocated by a piston mounted in acylinder I Iii supported in slot i2 of machine bed I 2 below and p 291 carried by slide I14.

42 and and rod I22. is carried byand secured to cradle end elements 43 and 45. when the cradle end elements are rotated about rod 4| into open and closedpositions each pair of plates H9 will be rotated about rod 4! into open and closed positions. Each plate H9 is semi-circularly cut away at I23 to embrace the tube being, formed into the corrugatedvessel as is well known in this-art. Each pair of plates I I9 may be kept in alignment by any suitable'means here shown as aligning spools I 24. Pairs of plates I I9 are urged togetherto the right, as seen in Figs. 1, 2 and'l, along rods 4i, I2I and|22by springs surrounding these rods, spring I25 surrounding rounding rod 4| being seen in Fig. 7 and spring I25 surrounding rod I2I being seen in Fig. 1. It will be understood that the number of pairs of plates I19, their thickness and the size of opening I23 will be determined by the number and size of corrugations andisize of tube as is well known in the art.

As seen in Figs. 3 and 4, each right-hand forming plate of each pair of formingplates H9 is provided with a latch'289 pivoted to the plate at 290 and provided with .a latch stud receiving opening 29L Eachleft-hand forming plate of each pair of forming plates I I9 is provided'with a latchstud 292 to be received in opening 29I. Cradle end elements 43 and 45 are providedfwith similar latches and cradle end elements 42 and 44 are providedwith similar latch studs. Lon.- gitudinally extending shafts 233 and 294 couple the several latches 289 together so that. they will operateas a. unit. The latch-239 carried by cradle end element .43 is provided with spaced fingers 295 and 296 designed to receive'finger As seen in Fig. 6, a tubular member 121 is slidably mounted on piston rod 93. Piston rod 93 has a collar I28 secured to its outer end. A spring I28 surrounds rod 93 within tubular member I21 and abuts collar I29 and the end of member I21 to urge member I 21 to the left asseen in this figure. Member I21 is centrally bored and threaded at I29 to receive closure member I30. Closure member vI30 is in turn centrally bored and threaded to receive the threaded shaft "I of ram I32, lock-nuts I33 being provided to=lock the ram assembly in position afterv adjustment. Ram I32, driven by the piston in cylinder I1 at the proper time in the cycle'of operation, eflects the movement of the pairs of plates II9 toward each other to form the corrugations. I

Mounted on the right end of machine bed II as seen in Fig. 1a are brackets I33 and I34 sup porting between them a cylinder I 35'the assembly being locked together by bolts I30. A piston is mounted in cylinder I35 and is provided with'a piston rod I31. Fluid under pressure is admitted to one side of cylinder I 35 through manually adjustable valve I38 and to the other side through manually adjustable valve I39. I

Piston rod I31 carries sealing head unit I 40 which is mounted for reciprocation on guide rods I 4| and I42 which are secured in parallel relationship at one endto bracket I33 and their Consequently;

other ends to bracket 24. Sealing head unit I is shown in enlarged detail in Fig. 8 and is there seen to comprise a body member I43 bored to receive bearings I44 and I45 which are mounted on rods I42 and MI respectively. Body I43 is centrally bored at I46 with reduced diameter at I41 to form annular shoulder I48. Mounted for movement in body I43 is member I49 provided with an annular shoulder I50 to engage shoulder I48 to form a stop in one direction of movement. Member I49 is externally threaded at I5I to receive lock ring I52 for nut I53. Member I49 is internally bored at I54 with reduced diameter at I55 to receive arbor base I56. Arbor base I56 is of reduced diameter at I51 to form a shoulder I58. A spring I59 embraces arbor base I56 and engages shoulders I58 and I60 to urge member I49 to the right as seen in this figure. Arbor base I56 is secured to body member I43 as by bolts I6I and is internally bored and threaded at I62 to receive piston rod I31.

Member I49 is internally bored and threaded at I63 to receive sealing collar I64. Arbor base I56 is internally bored and threaded at I65 to receive arbor I66. Slidably mounted on arbor I66 and within sealing collar I 64 are metal rings I61 and I68 separated by rubber ring I69. The inside diameters of these rings are slightly greater than the outside diameter of the tube to be corrugated. The diameter of arbor I66 is determined by the diameter of the tube to be formed into the corrugated wall so that the tube will fit loosely on the outer end of arbor I66 and snugly inside the sealing collar. The length of arbor I66 is determined by the finished length of the corrugated wall being formed.

Member I56 is centrally bored at I10 and arbor I66 is centrally bored at I1I in extension thereof so that fluid under corrugating pressure may be supplied to the interior of the tube on the arbor as will more fully appear hereafter.

The operation of the machine is controlled by a foot pedal I 12 (Figs. 1, 1a, 2 and 2a). Pedal I12 is mounted for rotation about a horizontal axis in a frame I13 secured at one end to tie rod I14 and supported at its other end by support rod I 15 which is secured at its upper end to machine bed II. Pivotally engaging pedal I12 is operating link I16 which is pivoted to bell crank I11 at I18. Bell crank I11 is mounted for rotation at I 19 on machine bed I I. A spring I acting on roller cam follower I 80 which engages centering cam surface I11 formed on the right edge of bell crank I 11 returns bell crank I11 to its neutral position when foot pedal I12 is returned to its neutral position. Arm I9I is mounted for rotation on bell crank I11 at I82 and terminates in an inwardly turned and hooked extension I 83. A lever I84 is rotatably mounted on machine bed I I at I85 and carries roller I86 to engage arm I8I A spring I81 is secured to lever I84 and to machine bed II to urge lever I84 into engagement with fixed stop I84. Bell crank I11 carries extension I 88 to which link I89 is pivoted at I90. Link I89 is slotted at I9I (Fig. 2a) to engage the actuating member of pilot valve I92 to reverse the operation of the machine as will appear more fully hereafter.

A connecting rod I93 is pivoted to arm I8I at I94 and is connected to rocker arm I95 at pivot I96. Rocker arm I95 is mounted for rotation on machine bed I I at I91 and is slotted at its upper end at I98 to receive the pin of clevis I99 carried by sliding rod 200. Rod 200 is mounted for longitudinal reciprocating movement in bearings 20I 8 secured to machine bed II (Fig. 2) and carries a lug 202 to actuate pilot valve 203. Rod 200 also carries a lug 204 which is engaged at the proper time in the cycle of operation of the machine by a dog 205 pivoted at 206 to arm 201 which is secured to shaft 208. Shaft 208 extends across machine bed II (Fig. 3) and is journaled for rotation therein. Dog 205 is biased into position to engage lug 204 by spring 209. Arm 201 is urged into clockwise rotation, as seen in Fig. 1, by a spring 2I0. Shaft 208 carries finger 2 (Fig. 3) which engages the underside of slide II4 so that downward movement of slide II4 will move finger 2II downward, rotating shaft 208 and arm 201 in a counterclockwise direction as seen in Fig. 1. Upward movement of slide II4 permits spring 2I0 to rotate arm 201 and shaft 208 in a clockwise direction as seen in Fig. 1 and to maintain finger 2I I in contact with slide II4.

Piston rod II1 carries an extension 2I2 (Fig. 2) to which a link 2I4 is pivoted at 2I3. Link 2I4 is pivoted at 2I5 to crank 2I6. Crank 2I6 is mounted for rotation at 2I1 on machine bed II and is so designed that its extension 2I8 will be rotated into engagement with the end of rod 200 when piston rod II 1 is in raised position. Extension 2I2 carries arm 2I9 extending downwardly outside machine bed II to which is secured a cam 220 to operate pilot valve 22I in the appropriate time in the cycle of operation of the machine as will appear more fully hereafter.

Sealing head unit I40 has rod 222 secured thereto for movement therewith (Fig. la). Rod 222 terminates in finger 223 which is designed to engage hooked extension I83 of arm I8I when sealing head unit I40 is in its withdrawn position. Rod 222 also carries a cam 224 which engages and operates pilot valve I 92 at appropriate times in the cycle of operation of the machine as will more fully appear hereafter.

The hydraulic system next to be described is shown in detail in Figs. l-2a and in simplified diagrammatic form in Fig. 9. Briefly this system comprises a source of fluid under pressure and a return thereto. Depression of foot pedal I12 to machine-run position shifts a pilot valve which in turn supplies fluid underpressure to open valves to supply fluid under pressure to the spacer reset cylinder and the sealing head unit cylinder, moving the spacer reset head to its outer position where it remains until the last stages of the cycle of operation of the machine. Fluid under pressure is also supplied to a pressure booster cylinder but not admitted at this time to the cylinder. As the spacer reset head moves, the sealing head unit with a tube on its arbor starts toward the open cradle. As the tube enters the cradle the sealing head unit operates a pilot valve which in turn opens another valve to admit fluid under pressure to the sealing head unit and the interior of the tube. As the sealing head unit finishes its stroke the tube is pushed against the ram in the end of the cradle and is seated firmly in the sealing head unit. Fluid pressure builds up in the tube and in the line thereto. This increased pressure operates a pressure responsive valve which opens to admit fiuid under pressure to the cradle operating cylinder to raise the piston therein and close and lock the cradle and forming plates about the tube. Upward movement of this piston shifts a pilot valve for the ram cylinder and mechanically locks the first pilot valve 9. against. any movement tendingnto reverse the machine.

As the cradle closing pistonreaches its upward position pressure builds up behind it and this increased pressure is used to open a pressure responsive valve. to admit fluid under pressure, previously supplied, to the pressure booster cylinder. The fluid under bulging pressure from this booster cylinder is then admitted to the tube and bulges the tube between the forming plates, as is well known in the art. When a predetermined bulging pressure has been reached in the tube a pressure responsive valve opens to admit fluid under pressure to a pressure responsive valve which in turn opens to admit iiuid under pressure to the ram. cylinder. The ram commences its stroke by withdrawing the spacers from between the forming plates and continues its stroke while the forming plates move together, collapsing thetube and forming thecorrugated wall. When the ram reaches the end of its stroke pressure builds up behind its piston and this increased pressure is used to bleed the high pressure fluid from the formed corrugated wall and the high pressure line. Loss of pressure in the high pressure line allows the pressure responsive valve associated with the cradle closing cylinder to supply fiuid to this cylinder to unlock and open the cradle and forming plates. Opening the cradle mechanically reverses the first pilot valve'described above and also shifts the pilot valve for the ram cylinder. Reversal of the first pilotvalve described above starts the spacer reset piston on its return or spacer reset stroke, starts the sealing head unit piston on its return stroke and starts the booster piston on its return stroke. Shifting of the pilot valve for the ram cylinder returns the ram to its initial position. On its return stroke the sealing head unit, carrying the finished corrugated wall on its arbor to a position outside of the cradle where it may be removed from the arbor by any suitable means, returns the pilot valve controlling the admission of fluid pressure to the tube to its original position. Return of the booster pistondraws a fresh charge of fluid into the pressure booster for the next cycle.

A machine setup valve is also provided in this hydraulic system by which the valve admitting fluid to the cradle operating cylinder and piston can be manually controlled to open or close the cradle independently of the cycle of machine operation during adjustment of the forming plates, spacers, etc.

Referring now to Fig. 9 which shows the hydraulic system for the machine, a pipe 225 leads from a source of fluid under pressure to a valve 226. Valve 226' is any suitable four-way, pilotoperated, hydraulic, directional flow control valve with its drain port connected by return pipe 221 to the source of fluid under pressure. Valve 226-is connected bypipe'228 and manually adjustable valve [9 to one side of spacer reset cylinder H6. The other side of spacer reset cylinder lil is connected through manually adjustable valve 23 and .pipe229 to the upper side of valve 226. A by-pass and check valve 236 is provided around valve 29. Valve 226 is connected through pipe 23l to a valve 232 which is a pressure operated, spring loaded, check valve. The other side of valve 232 is connected by pipe 233 to the lower side of pressure booster cylinder 234. A by-pass and check valve 235 is provided from pipe 233 around valve 232 and back to 10 pipe 23l. A pipe 236 leads from pipe23l, through manually adjustable valve l38;to. one side of sealinghead unit cylinder. I35 andthe other side of cylinder I35 is connected through manual ly adjustable valve I39 by pipe 231 to pipe'226. Pipe 238 connects the upper endef booster cylinder 234 to the upper side of valve 226. I

The hydraulic system operating the cradle opening and closing cylinder and; piston H6 includes a pipe 239 leading through a manually operable valve 246 to valve 241. Valve-2H is any suitable four-way,pilot-operated, hydraulic, directional flow, control valve with an adjustable spring in place of the pilot pressure cap to return the valve spool uponrelease of pilot pressure. Valve I is connected by pipe 242 to the lower end of cylinder 6 andis connected bypipe 243 to the upper end of cylinder H6. Pipe 244connects the drain side of valve 24]; to pipe 221. i

The hydraulic system operating .the ram piston and cylinder l1 includes pipe 225 connected by pipe 245 to valve 246 which is any suitable, four: way, pilot-operated, hydraulic, directional flow, control valve. The drain side of valve 246 is connected by pipe 241to pipe 221. Valve 246 is connected to the left side of cylinder l-1through pipe 248, manually adjustable valve 249 and check valve 256 and is connected to; the other;

side of cylinder l1 through pipe 251.. The left side of cylinder 11 is connected-to return line 221 by pipe 252, pilot valve Y22! and pipe ;2 53.,

The pressure booster system-is seen in Figs. la, 2a and 9 and isdescribed with particular referenceto Fig. 9. The piston incylinder 234 drives a piston of smaller area in cylinder 254'. The pressure increase is inproportionto the ratio of these areas. The upper end of cylinder 254 is connected by pipe 255 topipe .256 which is in turn connected through check. valve 251- to a source 258 of fluidunderpressure Pipe 256 also connects into valve 259 which is anysuitable four-way, pilot-operated, hydraulic, directional flow, control valve with one port closed. .The upper pressure cap of valve 259 is elongated and contains a spring to bias the valve spool against the other pilotpressure cap and into drain posi tion when pilot pressures are equal in bothtcaps.

.The drain port ofvalve 2 59 is-.connected -by pipe 26ll'to drain pipe 26L Valve-259is' connected by pipe 262 to valve'263 which is an adjustable, balanced type, pressure control valve ofthe unloading type used'to set and maintain tube bulging pressures. Valve 263 is connected by pipe 264 to manually adjustable valve 265 and through flexible conduit 266 to the central: boring l10of member I56 and boring "I of arbor I66 (Fig. 8). A pressure gauge 261 may be inserted in pipe 264 if desired. Valve 263 is connected by pipe 268 to valve 269. Valve 269 is any suitable, reverse acting, bellows operated, poppet type, regulator.

valve connected by pipe 210 'to drain pipe 26l. Pipes 2H and 212 connect pipe 268 tothe bellows of valve 269. r

The hydraulic system for operating thesev eral pilot valves above described includes a pipe 213 connecting pipe 225 with machine setup pilot valve 214 and furnishes fluid-under pressure to valve 214. Pilot valve 214 furnishes fluid under pressure to the other pilot valves when in normal operating position. The drain port of valve 214 is connected by pipe 215 to pipe'221. Valve 214 supplies fluid under pressure when in normal operating position to pilot valve 203 through pipe 216. Pilot valve 203 is connected by pipe 211 to one pilot pressure cap of valve 226 and is connected to the other pressure cap by pipe 218. Valve 203 supplies pressure to pilot valve I92 through pipe 219. Pilot valve I92 is connected to the elongated pressure cap of valve 259 by pipe 280 and to the other pressure cap by pipe I. A pipe 282 connects pilot valve I92 and pilot valve 22 I.

Pipe 264 is connected by pipe 283 to three-way valve 284, which is connected to pilot valve 214, and by pipe 285 to the pressure cap of valve 24I. Three-way valve 284 when in normal operating position closes the connection to pilot valve 214 and opens the connection between pipes 283 and 285.

Pipe 21I is connected by pipe 286 to one pressure cap of valve 246. The other pressure cap of valve 246 is connected by pipe 281 to the upper end of cylinder H6. The lower end of cylinder H6-is connected by pipe 288 to the pressure operating mechanism of valve 232.

With the mechanical elements and the hydraulic operating system of this machine set up as above described, when it is desired to manually control the opening and closing of the cradle independently of the cycle of operation of the machine, as when replacing or adjusting forming plates, spacers, spacer separators or for other purposes, three-way valve 284 is rotated to cut oil pipe 283 and connect pipe 285 to pilot valve 214. Manual operation of pilot valve 214 then supplies fluid under pressure from pipes 225 and 213 to pipe 285 and the pressure cap of valve 24I. Valve 24I then opens to admit fluid under pressure from pipes 225 and 239 to pipe 242, valve 240 being manually adjusted to obtain the desired rate of flow of fluid in pipe 242. Fluid under pressure is supplied from pipe 242 to the lower side of the piston in cylinder I I6 raising the piston and piston rod I I1. Upward movement of rod H1 through link H8 moves slide H4 and rollers I I2 upwardly. Upward movement of rollers H2 rotates arm I08 in a counterclockwise direction and arm I09 in a clockwise direction as seen in Figs. 3 and 4 rotating shaft 94 in a counterclockwise direction and shaft I03 in a clockwise direction. counterclockwise rotation of shaft 94 rotates rocker arms 95 and 99 in a counterclockwise direction and through links 96 and I rotates cradle end elements 42 and 44 about rod H in a counterclockwise direction to closed position.

Clockwise rotation of shaft I03 imparts the same rotation to rocker arm I04 and through link I08 to cradle end elements 43 and 45 rotating these end elements into closed position. Slide I I4 has only partially completed its upward movement when the cradle end elements reach their closed position. By reason of the shape of slots H0 and III in arms I08 and I09 slide H4 is enabled thereafter to continue its upward movement. Rotation of the cradle end elements also rotates the pairs of forming plates I I 9 since each pair of forming plates H9 is pivoted on rod M and supported for movement with the cradle end elements by rods I2I and I22. The spacer assembly also rotates with the crad e end elements and the spacers remain between the pairs of forming plates. As the cradle end eements move into closed position fingers 295 and 296 are moved into the path of upward movement of finger 291 and as slide I I4 contin 'es its Upward movement af ter the cradle end elements and pa rs of lat s H9 have-reached closed position finger 2" engages between fingers 295 and 9-" and rotates all of the latches 289 into position where they engage latch 12 studs 292, locking the cradle end elements and pairs of plates I I9 together.

When pilot valve 214 is manually shifted to its original position pressure is relieved in the pressure cap of valve 24I and valve 24I under action of its spring opens communication between pipe 225 and the pipe 243 supplying fluid under pressure to the top of cylinder I I6 and connecting pipe 242 through pipe 244 to return pipe 221. The piston in cylinder I I6 starts downwardly and moves piston rod I I1 in the same direction. Slide H4 moves downwardly and during the first part of this movement finger 291 opens latches 289. After latches 289 have opened, further downward movement of slide H4 reverses the rotation of the several elements above described and the cradle end elements open carrying the forming plates and separator assemblies with them, opening the pairs of plates I I9.

After suitable adjustment of the cradle assembly has been made and it is desired to operate the machine in its automatic cycle, valve 284 is rotated to its normal position closing its connection to pilot valve 214 and opening communication between pipes 283 and 285. A tube is then placed on arbor I66 and foot pedal I12 depressed to draw link I16 downward rotating bell crank I11 about its pivot I19 in a counterclockwise direction. counterclockwise rotation of bell crank I11 moves arm IBI to the right since hooked extension I83 is engaged by finger 223. Movement of arm I8I to the right through rod I93 rotates rocker arm I in a clockwise direction and pilot valve 203 is moved by rod 200 and cam 202 to machine run position. counterclockwise rotation of bell crank I11 has no influence on pilot valve I92 because of slot I9I in link I89. With pilot valve 203 in machine run position fluid under pressure is supplied from pipe 225 through pipe 213, pilot valve 214, pipe 216 and pilot valve 203 to pipes 218 and 219. Fluid pressure in pipe 218 operates valve 226 to admit fluid under pressure from pipe 225 into pipes 228 and 236 to start the spacer reset piston and the sealing head unit piston in movement. Pressure is also supplied to pipe 23I but backs up against closed valve 232 and check valve 235. The spacer reset head 3I is moved to its outward position and remains there until later in the cycle.

Movement of the sealing head unit piston moves sealing head unit I40 to the left as seen in Figs. 1 and 1a and finger 223 releases arm I8I. Further movement of sealing head unit I40 to the left brings cam 224 into engagement with pilot valve I92, operating this valve to supply fluid under prsesure from pipe 219 through pilot valve I92 to pipe 28I and valve 259. Valve 239 is operated to admit fluid under pressure from pipe 258 into pipe 264, flexible pipe 266 and the interior of the tube on arbor I66 just before the tube engages ram I32. Movement of the sealing head unit I40 continues until the end of the tube on arbor I66 comes into engagement with ram I32. The open end of the tube is then pressed into sealing collar I64 and rings I61, I68 and I69 seal the open end of the tube against loss of pressure by squeezing rubber ring I69 inwardly against the tube. Back pressure then builds up in pipes 266 and 264 and passing through pipes 293, valve 264 and pipe 285 operates valve 24I. Valve 24I then admits fluid under pressure from line 225 to pipe 262 and the underside of the piston in the cylinder II 5 which moves upward closing and locking the cradle and pairs of forming plates i9 abo at the tube as above described.

When the piston in cylinder IIG reaches the top of its stroke pressure builds up behind 'it and is taken by pipe 288 to valve 232 and valve 2321s opened admitting fluid under pressure from pipe 225, valve 229 and pipes 23I and 233to the.bot-. tom of booster cylinder 234; The piston .in cylinder 234 moves upward and fluid under bulging pressure backs up against check valve 251 and passes through pipes 255 and 259, valve 259, pipe 292, valve 263, pipe 264, valve 285, flexible pipe 269 and borings I and Ill to the interior of the tube bulging the same between the forming plates as is well known in the art. 1

As soon as the bulging pressure for which valve 263 is preset is reached valve 263 unloads and admits fluid under pressure to pipes 21I and 286. Valve 246 is operated by this fluid pressure to admit fluid under pressure from pipe 225 through pipe 248, valve 249 and check valve 250 tothe left side of cylinder I1 starting the piston-in this cylinder on its. ram stroke. Valve 269 is pressure operated to assure the right amount of ressure in pipe 21I. It will thus be seen that by reason of this interrelation of pressures the ram'stroke cannot start until the proper bulging-pressure has been reached and the tube bulged be ween the forming plates.

'14 (Fig. 9) has now been released, to admit fluid urlder pressure from pipe 225 to pipe l. The piston in cylinder I1 cannot start its return stroke however until the downward movement of piston rod H1 and cam220 operates pilot valve 221 to drain cylinder I1 through pipe 252, pilot valve 22 I, pipe 253 and pipe 221. "Drainage cannot take place through pipe 248 because of check valve 250. A safety feature is thus provided preventing the ram [32 from returning to its starting position until the cradle is completely open and the pairs of forming plates I I 9 removed from the now corrugated wall. As piston rod 93-nears the end of its return stroke cam 92 clears cam engaging elements 99 and 9| and these drop inbehind cam 92 in readiness for the next cycle of the machine. Final movement of piston rod 93 in this direction compresses spring I28 in the lost motiondevice in tubular member I21 since motion of member I21 is stopped by bracket 23 and sets the lost motion device "for the next machine 1 cycle.

Ram I32 does not start its compression stroke 7 until a predetermined movement of. piston rod 93 has occurred. This lost motion is provided by piston rod 93 sliding in cylinder I21 until ring I29 engages the end of closure member 39. During this lost motion cam 92 advances and. forces cam followers 85 and 81 outwardly (Fig.6) rotating arms 80 and 82.0utwardly which in turn'rotates shafts 84 and 85 and arms 8| and 93 outwardly. Outward rotation of arms. 89, SI, 82. and 83 carries bars 14 and 15 with them and these bars engaging in slots 62 of spacers 58 move spacers 59 from between the pairs of forming plates II9. Thereafter piston rod 93 picks up ram I32' and moves ram I32 on its compressing stroke-as the pairs of die plates move togetherand completing the corrugations. I

When the piston in cylinder I1 re'achesth'e end of itsram stroke pressure builds up behind it and is taken through pipe 252 to pilot valve 22 I Valve 22I has meanwhile been actuated on the upward stroke of piston rod I I1by cam 229-to admit-this fluid pressure to pipe 292, pilot valve I92 and pipe 280 to valve 259 where it balances valve 259 and allows the valve spring to move the valve poppet of valve 259 to drain position and the high pressure system is drained through pipes 259 and 26I.

Release of pressure in the high pressure system releases pressure in pipes 283 and 285 and valve 24I is returned by its spring to admit fluid under pressure from pipe 225 to pipe243 and the top of cylinder N 6. The piston in cylinder I-I6 then starts down and fluid beneath it drains through pipe 242, valve 2M and pipe 244 to pipe 221. Downward movement of this piston and its rod II1 unlocks the cradle end elements and forming plates as above described and rotates them to open position.

Downward movement of slide I I4 rotates finger 2| I and shaft 298, rotating arm 29-1 counterclockwise as seen in Fig. l, and dog 205, which snapped under lug 204 on the upward movementof slide I I4, engages lug 294 and slides rod 290 to the left reversing pilot valve 293. Y

Asthe piston in cylinder H6 finishes its dowm ward movement pressure builds up behind it and is taken by pipe 281 to one pressurecap of valve 2.46.0perating valve 246, since pressure in pipe 286 The reversal of pilot valve 293 described above admits fluid under pressure from pipe 225, pilot valve 214 and pipe-21B to pipe 211 actuating valve 225 to admitfiuicl under pressure from pipe 225 to pipes 229 and 233. Fluid under pressure in pipe 229 passes through-pipe 231 and valve I39 to cylinder I35 starting the sealing head unit piston on its return stroke, the fi'uid behind this piston draining through valve I38, pipe 236 and valve 228 to pipe 221, valve 232 having meanwhile been closed by its spring when cylinder IIB draining.

through pipe 242 drained pipe 289. Return of sealing head unit I45 to its starting position through the action of cam- 224 returns pilot valve I92'to its starting position and finger 22'3engages hooked extension I83 of arm I8I Arbor I of sealing head unit I 49 carries the finished corrugated wall with it clear of the cradle and atthis time the corrugated wallmay be removed from arbor I65" by any suitable means, manual or mechanical, and another tube placed onarbor I I6 for the next cycle of the machine.

Fluid under pressure in pipe 229 backs up against check valve'239 and passing through valve 20 starts the piston in the spacer reset cylinder IS on its movement to the left which is the work stroke for this piston. Fluid drains from cylinder I6 onthis stroke through pipe 228' and valve 226 to pipe 221. 1 As best seen in Figs. 4 and 7, at'the time of'this work stroke the cradle is open and the spacers 58 in their withdrawn position are in the path of movement of rollers 39' and 49. As spacer reset head 3I moves to the left drawn by piston rod 32 and the pist'onin cylinder I9, rollers 39 and 40 are rolled over and engage cam surfaces 64 of spacers 58 moving spacers 58 inwardly. The oifset centers of rollers 39 and 49 permit this movement to take place without shock and over a longer period of time. spacers 58 move cam surfaces 63' thereof between the pairs of forming plates II9 separating. the pairs of forming plates II9 against the compression of springs I25 and I26. Inward movement'of spacers 58 is continued until the bodies of spacers 58 are between the pairs. of forming plates H9 and the pairs of forming plates II9 are in proper spaced relationship for the next machine cycle. Movement of spacers 58 inwardly carries bars 14 and 15 inwardly and rotates arms 89, 81, 92 and 83 inwardly.

Fluid under pressure in pipe 238 starts the booster piston in cylinder 234 on its return stroke, the fluid in this cylinder exhausting through pipe 233 and check valve 235 to pipe 231 and valve 225 Inward movement of to pipe 221. Downward movement of the piston in cylinder 234 moves the piston in cylinder 254 downward drawing a fresh charge of fluid into cylinder 254 through check valve 251 and pipe 258 for the next cycle of the machine,

The machine is now ready for the next cycle of operation and if foot pedal I12 is kept by the operator in depressed position it will start its next cycle automatically and without pause. If foot pedal I12 has been released the machine will stop until the pedal is again depressed to depress link I16 to shift pilot valve 203 to machine run position.

Reversal of the machine may be initiated at any time in its cycle of operation and thereafter the several elements of the machine will return to their initial positions in their proper sequence. The machine is reversed by movement of foot pedal I12 to raise link I16 to rotate bell crank I11 in a clockwise direction as seen in Fig. la. If the sealing head unit I has not yet shifted pilot valve I92 so that the cradle has closed and rotated bell crank 2I6 into engagement with the end of sliding rod 200, the reversal of the machine is performed by the direct reversal of pilot valve 203. Under these circumstances clockwise rotation of bell crank I11 rotates pivot I82 in the same direction and the same movement is imparted to arm I8I which is rotated about cam roller I86 on cam arm I84. Link I93 is thus moved to the left, rotating rocker arm I95 in a counterclockwise direction which in turn slides rod 200 to the left reversing pilot valve 203 by action of lug 202. The machine then reverses and the several elements return to their initial positions in proper sequence as above described.

If the sealing head unit I40 has shifted pilot valve I92 so that the cradle is closed and the operator actuates foot pedal I12 to reverse the machine, pilot valve 203 cannot be reversed since bell crank 2I6 has been rotated into engagement with the end of sliding rod 200 locking pilot valve 203 in machine run position. Link I93 is also held against movement and clockwise rotation of bell crank I11 rotates arm I8I about pivot I94 moving cam roller I86 and cam arm I84 in clockwise rotation. Clockwise rotation of bell crank I11 draws link I89 to the right and as the actuating element of pilot valve I92 has been shifted by sealing head unit I40 to the left end of slot I9I (Fig. 2a) link I89 reverses pilot valve I92. Reversal of pilot valve I92 supplies fluid under pressure to pipe 280 shifting valve 259 to drain position, draining the high pressure system of the machine and effecting reversal of the several elements and their return in sequence to their initial positions as above described. It will now be apparent that no matter at what point in its cycle of operation the machine is reversed the several elements thereof will be returned to their initial position in proper sequence without damage to the machine.

A modified piping layout is partially and schematically shown in Fig. 12. This system dispenses with certain of the parts in the system above described, notably pilot valve 22I and three-way valve 284, and utilizes any suitable four-way, pilot operated, hydraulic, directional flow, control valve with two ports blocked in place of pressure operated, spring loaded check valve 232. The cycle of operation of the machine is, however, exactly the same. In this system when the machine cycle is started by actuating pilot valve 203 fluid under pressure is admitted to pipe 218 which actuates valve 226 to admit fluid under pressure to pipes 228, 236 and 23I as before. Fluid under pressure is also admitted to pipes 29I and 292 to assure that valves 246 and 232 remain closed. When pressure builds up in pipe 264 it is taken by pipe 285 in this system through pilot valve 214 and pipe 293 to one pressure cap of valve 24I to actuate valve 24I to close the cradle. Pressure built up when the cradle is closed passes through pipe 288 to one pressure cap of valve 232 to open valve 232 and admit fluid under pressure from pipe 23I to pipe 233 and cylinder 234. When bulging pressures are reached valve 263 unloads as before and valve 246 is actuated to drive the ram. Pressure built up when the ram reaches the end of its stroke is taken by pipe 252 to one pressure cap of valve 259 to bleed the high pressure system and to supply fluid under pressure to pipe 290 which is connected to one pressure cap of valve 2 to actuate valve 24I to supply fluid under pressure to open the cradle and return the ram to its initial position. Opening of the cradle shifts pilot valve 203 as before and the reversal of the machine proceeds as above described.

As will be apparent, adjustment of the handoperated valves heretofore referred to enables the rate of flow therepast and the development of pressure therebeyond to be nicely predetermined so that the desired intervals of time will transpire between the successive operations in the sequence described, and where pressure responsive valves are used proper selection of the actuating pressure as well understood in the art will effect a like result.

It will now be apparent that the present invention provides a novel hydraulic press for forming expansible and contractible corrugated metallic walls in which the several steps are performed automatically at the proper time. When the tube is in place in the cradle and between the open forming plates means are automatically actuated to close the open end of the tube, after which controlled hydraulic pressure, thereafter bulging and hydraulic pressure supplied by novel pressure booster means is admitted automatically to the interior of the tube to form bulges in the tube between the pairs of forming plates. The spacers between the pairs of forming plates are then automatically removed and thereafter novel means are automatically actuated so that the pairs of forming plates approach each other to complete the formation of the expansible and contractible corrugated wall. Novel automatic means are then provided to drain the liquid under pressure from the system leading to the finished wall as soon as it is formed, and thereafter to unlock and open the cradle and withdraw the corrugated wall from the forming plates. Novel means are provided for automatically interposing the spacers between the several pairs of forming plates before the start of the next forming cycle, it also being apparent that the present invention provides novel means for looking the forming plates of each pair together and novel means for rotating the forming plates into and out of closed position to allow their ready removal and adjustment.

To those skilled in the art changes in or modifications of the above described illustrative embodiment of the present invention will now be suggested without departing from the inventive concept of the present invention. For instance emcee? if; metallic tubes having; both ends, open are to be'formed into the expansible. andcontractible to operate together and to both admit hydraulic pressure to thetube at the same; time. In such a. situationas this the second end sealing assembly, with properpressure booster means, as described, would be mounted on piston rod 93 in place of ram I31! and would have the dual function of both endsealing. the tube and compressing the bulged tube to form; the expansible and contractible metallic wall. Further and other changes in the hydraulic system, in the spacer assembly, in the various locking devices, etc, will now be suggested to those skilled in. the art, and therefore to determine the scope of the present invention reference should be had to the appended claims, I

What is claimed is;

1. In an apparatus of the character described, in combination with-pairs of cooperating forming plates, pairs of frame elements mounted for rotational movement into open and closed positions in which corresponding plates of said pairs are slidably mounted for relative rotational movement, a source of fluid pressure,.means for rotating said frame elements and plates into closed position and for locking said frame elements and the plates of -,said. pairs: together, movable means for automatically closing the open end of a tube in position in said plates before said plates are in closed position, a valve responsive to movement of- .saidlast named means for admitting, fluid under pressure to the interior of the tube, when said last named 111634118115 in tube closing position, and a pressure responsive valveresponsive. tothe pressure in the tube for energizingsaid rotating means to rotate said frame, elements and plates into closed positionabout the tube.- V

2. In an apparatus of the character described,

in; combination withpairs ofcooperating iorrne ing plates, a frame a in' which; corresponding plates of said pairs are rotatably and slidably mounted, a source of fluid -pressure,fluid pres- Said valve, 8 pressure responsivevalve TBSIJOD- sive to. the pressure in said conduit to energize said rotating and locking means, means arranged to be connected, with said source of fluid pressure for increasing the pressure thereof, to a bulging pressure, fluid pressure means, actuated by the fluidpressure in. said rotating and locking means to connect saidsource of fluidpressure with said means, for providing a bulging pressure, and

means for connecting saidv means fordeveloping bulging pressure through said tube endsealing means to the, interior of the tube only after the plates are in closed and locked position.

3.. In an, apparatus of the character described,

in combination withv pairs of cooperating forming plates, a frame in which corresponding Plates of said pairs are rotatably and slidably mounted, a source of fluid pressure, fluid pressure means for rotating andfor locking the plates of said pairs together, means for sealing the. open end of a tube supported in position in said plates,

means for moving said sealing'means and the tube into sealing relation before said platesare in locked position, a valve for admitting fluid under pressure to the interior of the tube, means responsive to movement of said last named means for actuating said valve, 2. pressure responsive valve responsive to pressure in the tube for energizing said rotating and locking means, a pressure booster adapted, to be connected to the interior of the tube through said sealing means, a pressure controlvalvebetween said pressure booster and said sealing means, and fluid pressure means actuated by the fluid pressure in said rotating and locking meansfor-automatically connecting said source of fluid pressure to said pressure booster after said plates are locked together, said pressure booster communicating with the interior of the tube through said sealing means and said pressure control valve operating to maintain asubstantially uniform pressure in the tube while bulges are being formed in the tube between said plates.

4. In an, apparatus of the character described, in combination with pairsof cooperating forming plates, -a frame in which corresponding plates of said pairs are rotatably and slidably mounted, a source of fluid pressure-fluid pressure means for rotating and for locking the plates of said pairs together, spacers adapted to be inserted between the respective pairs of plates, means for supporting a tube and for sealing the open end of the, tube in position in, said plates before said plates are locked together, cam means forwithdrawing said spacers, a ram for actuating said cam means and for collapsing said tube axially, a cylinder and piston for operating said ram, means actuated by the fluid pressure in said rotating and locking means as said plates are locked together for connecting saidsource of fluid pressure with the interior of said tube to bulge said tube between said plates and means connecting said source of fluid pressure with said cylinder to actuate said ram and said cam means to withdraw said spacers only after bulge forming pressure has beenestablished in said tube and thereafter to move said ram to collapse said tube axially.

5. In an apparatus of the character described, in combination with pairs of cooperatingtormingplates, a frame in which corresponding plates of said pairs are rotatably and slidably mounted, a source, of fluid pressure, fluidpresram for collapsing said tube axially, a cylinder and piston for operating said. spacer withdrawing means and, said ram, means actuated by the fluid pressure in said rotating and locking means as said plates arev locked together for connecting; said source of fluid. Pressure with' the interior of thetube to bulge the tube between said plates, means connecting said source of fluid pressure with said cylinder to' withdraw said spacers'only after bulgei'ormingpressure has been established in the tube and to there- 

